This document relates to wireless communications in wireless communication systems.
Wireless communication systems can include a network of one or more base stations to communicate with one or more wireless devices such as fixed and mobile wireless communication devices, mobile phones, or laptop computers with wireless communication cards that are located within coverage areas of the wireless systems. Base stations can emit radio signals that carry data such as voice data and other data content to wireless devices. A base station can transmit a signal on a forward link (FL), also called a downlink (DL), to one or more wireless devices. A wireless device can transmit a signal on a reverse link (RL), also called an uplink (UL), to one or more base stations. Further, a wireless communication system can include a core network to control the base stations.
A wireless device can use one or more different wireless technologies such as orthogonal frequency-division multiplexing (OFDM) or code division multiple access (CDMA) based technologies for communications. Various examples of standards for wireless technologies include Long-Term Evolution (LTE), Universal Mobile Telecommunications System (UMTS), CDMA2000 1×, Worldwide Interoperability for Microwave Access (WiMAX), Global System for Mobile Communications (GSM), and General Packet Radio Service (GPRS). In some implementations, a wireless communication system can include multiple networks using different wireless technologies. A wireless device can be referred to as user equipment (UE), access terminal (AT), a mobile station (MS), a mobile device (MD) or a subscriber station (SS). A base station can be referred to as an access point (AP) or access network (AN). Examples of base stations include Node-B base stations and eNode-B base stations.